The present invention relates to a method and an apparatus for monitoring a catalytic converter and more particularly, to a method and an apparatus which employs several sensors which cooperatively gather exhaust gas data and which analyze the gathered data in order to determine whether the catalytic converter is properly functioning and/or operating.
Monitoring apparatuses or assemblies and methods for employing or utilizing such monitoring apparatuses or assemblies allow for the selective monitoring of certain vehicle systems or components, effective to determine and/or ensure that such systems and/or components are properly functioning. Particularly, it is desirable to monitor such vehicle systems or components in order to quickly identify system and/or component failure and/or malfunction and to provide notification of such a failure or malfunction to an operator and/or user of a vehicle in order to allow the failure and/or malfunction to be readily and properly corrected and/or addressed. One type of vehicular system which may be desired to be monitored in this manner is a vehicular exhaust system of the type which includes a catalytic converter.
In a conventional combustion engine, air and fuel are selectively injected or placed into several combustion chambers and are operatively mixed or combined. The air and fuel combination or mixture is then ignited, in each chamber, thereby causing the mixture to combust within each of the combustion chambers and xe2x80x9cdrivingxe2x80x9d or moving the pistons which are operatively and respectively disposed within the chambers. The xe2x80x9cbyproductsxe2x80x9d or xe2x80x9cexhaust gasxe2x80x9d, which is produced and/or formed by the combusted air and fuel mixture, exits or leaves the combustion chambers and flows or travels to the exhaust manifold. The exhaust manifold then typically communicates the received combustion byproducts or exhaust gas to the catalytic converter where the xe2x80x9cbyproductsxe2x80x9d are xe2x80x9ctreatedxe2x80x9d in a conventional manner and communicated to a vehicle exhaust assembly.
When the ratio of air to fuel within the combustion chambers is xe2x80x9coptimumxe2x80x9d or xe2x80x9cidealxe2x80x9d, the produced exhaust gas is composed primarily of carbon dioxide and water. When this ratio is xe2x80x9crichxe2x80x9d (i.e., when the combustion chambers contain a substantially larger amount of fuel than is xe2x80x9coptimalxe2x80x9d or xe2x80x9cidealxe2x80x9d) or is xe2x80x9cleanxe2x80x9d (i.e., when the combustion chamber contains substantially less fuel than is xe2x80x9coptimalxe2x80x9d or xe2x80x9cidealxe2x80x9d), the exhaust gas contains certain undesirable constituents. Typically, these undesirable constituents include xe2x80x9coxidantsxe2x80x9d and/or xe2x80x9creductantsxe2x80x9d.
Within the catalytic converter, the received oxidants or reductants react with certain contained reaction-causing elements or xe2x80x9ccatalystsxe2x80x9d. For example and without limitation, the catalysts cause the received oxidants to be operatively xe2x80x9cstoredxe2x80x9d within the catalytic converter until reductants are produced by the previously delineated combustion process and is communicated to the catalytic converter. The catalysts then cause the stored oxidants to react with the subsequently communicated reductants to desirably produce carbon dioxide and water. When the catalytic converter is not working properly, this desired reaction no longer takes place and various types of undesirable elements or materials are produced and are discharged or emitted from the catalytic converter.
It is therefore desirable to monitor the effectiveness or operability of the catalytic converter. More particularly, it is desirable to detect or monitor the catalytic converter in order to determine whether the catalytic converter is and/or remains effective to produce the desired emissions. When the catalytic converter is no longer producing the required emissions, it is desirable to detect this condition, to inform an operator/user of the vehicle of this condition, and to replace the catalytic converter.
Prior xe2x80x9cstrategiesxe2x80x9d and/or monitor assemblies have been used or employed to detect the continued effectiveness or operability of a catalytic converter. Many of these prior methods or strategies require the acquisition of relatively extensive amounts of data which is often obtained by intrusively xe2x80x9cmodifyingxe2x80x9d or placing sensors and/or components within the catalytic converter. The obtained data is then utilized to determine the effectiveness of the catalytic converter. Further strategies include removing the catalytic converter from the vehicle and performing operability tests on the catalytic converter.
These prior catalytic converter monitoring systems, methods, and/or strategies have certain drawbacks. For example and without limitation, many of these prior systems, strategies, and processes are relatively costly and expensive to implement and perform, and require the vehicle to be serviced and/or to be inoperative (e.g., the vehicle is inoperative when the catalytic converter is removed from the vehicle). Furthermore, many of these prior systems, strategies, and processes are relatively difficult to use, relatively time consuming to employ, and require attachment to and/or modification of the catalytic converter or certain portions of the converter. Moreover, such prior catalytic converter monitoring systems are substantially and undesirably intrusive to the vehicle exhaust system and/or to the overall operation of the vehicle.
There is therefore a need to provide a method and apparatus for monitoring a catalytic converter which overcomes some or all of the previously delineated drawbacks and which selectively allows for the monitoring of a catalytic converter in a relatively efficient, cost-effective, relatively easy, and non-intrusive manner.
It is a first object of the present invention to provide a method and apparatus to monitor a catalytic converter which overcomes some or all of the previously delineated drawbacks of prior catalytic converter monitoring methodologies and/or strategies.
It is a second object of the invention to provide a method and apparatus for monitoring a catalytic converter which overcomes some or all of the previously delineated drawbacks of prior catalytic converter monitoring methodologies and/or strategies, and which efficiently and reliably detects or determines whether the catalytic converter is and/or remains operable.
It is a third object of the invention to provide a method and apparatus for monitoring a catalytic converter which detects the effectiveness of the catalytic converter in a manner which is non-intrusive to a vehicle, to the vehicle operation, and/or to the vehicle exhaust system.
It is a fourth object of the invention to provide a method and apparatus for monitoring a catalytic converter which detects the effectiveness of the catalytic converter in a manner which is cost-effective and which is relatively easy to employ.
It is a first aspect of the invention to provide an apparatus for use in combination with a catalytic converter of the type which selectively receives a first material and which uses the received first material to create and output a second material, the catalytic converter having a sensor which uses the second material to create and output a signal. The apparatus comprises a controller which is communicatively coupled to the sensor, which receives the signal, and which compares the signal to at least one value, and, based upon the comparison, determines whether the catalytic converter is operational.
It is a second aspect of the invention to provide a method for monitoring a catalytic converter having an inlet portion and a first outlet portion and operatively connected to an engine having an air intake portion and a second outlet portion communicatively connected to the first inlet portion; providing a first sensor which is operatively connected to the first outlet portion, and which generates a first signal; providing a second sensor which is communicatively coupled to the air inlet portion, and which generates a second signal; providing a controller, effective to receive and utilize the first and second signals, thereby determining if the catalytic converter is operational.
These and other features, aspects, and advantages of the invention will become apparent by reading the following specifications and by reference to the following drawings.